Windex contains ammonia, according to Apple it's not safe to use on screens: > Don't use window cleaners, household cleaners, aerosol sprays, solvents, ammonia

Windex contains ammonia, according to Apple it's not safe to use on screens: > Don't use window cleaners, household cleaners, aerosol sprays, solvents, ammonia, abrasives, or cleaners containing hydrogen peroxide to clean the display. https://support.apple.com/en-us/ht204172 https://support.apple.com/en-us/ht204172 Stick with a damp cloth. (I use 99% isopropyl alcohol to clean my computer, screen and all. It's notably absent from Apple's list of forbidden chemicals, but I'm not sure that it's safe so I won't recommend it.)